Topcoat Compositions, Coated Substrates, and Related Methods

ABSTRACT

An aqueous based topcoating formulation is provided to coat various substrates such as those used in offset and electrographic printing devices. The water based coating formulation includes ethylene acrylic acid copolymer, polyethyleneimine, and a suitable crosslinker. The formulation exhibits excellent adhesion to substrates and excellent anchorage with different printing inks.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims priority to U.S. Provisional ApplicationNo. 61/746,713 filed Dec. 28, 2012, which is incorporated herein byreference in its entirety.

FIELD

The present subject matter relates to coating compositions such astopcoat compositions, substrates having coatings of the compositions,and related methods. In particular, the subject matter relates tocoatings used in printing and barrier applications.

BACKGROUND

It is well known to apply a primer coating or “topcoat” to a paper orfilm substrate in order to improve bonding or anchorage of subsequentlyapplied inks, toner, or other materials to the substrate. Theformulation of the coating typically depends upon numerous factors suchas the nature of the substrate and the printing media, i.e. the inks,toner or other materials. The characteristics of the coating can alsodepend upon the particular type of printing process to be used inapplying the ink or toner. Although numerous types of coatings areknown, many of which provide satisfactory performance, a need remainsfor coating compositions which exhibit improved properties as comparedto currently known compositions.

It would also be beneficial to provide primer or topcoat compositionswhich could be used in association with a variety of different printingprocesses. For example, in view of the increasing popularity of HPIndigo printing, UV printing, and inkjet printing; it would be desirableto provide a single class of compositions which could be used in all ofthese processes. That is, although certain compositions may providesatisfactory results for one type of printing process, frequently suchresults do not extend to use of the same composition to other printingprocesses.

More specifically, ink anchorage for HP Indigo printing applications istypically poor and difficult to achieve for certain substrates. This isbelieved to be due to at least two factors. One factor may relate to thetype of substrate. For example, it is difficult to achieve good topcoatadhesion to certain substrates such as polypropylene and cast glosspaper. A second factor relates to compatibility difficulties betweenmany inks and the topcoat. For HP Indigo printing techniques, thetopcoat must be relatively polar and compatible with the ink to beapplied thereto. Therefore, it would be beneficial to provide a topcoatwhich exhibits good adhesion to substrates such as polypropylene andcast gloss paper; and which is relatively polar and compatible with inkstypically used in HP Indigo printing.

SUMMARY

The difficulties and drawbacks associated with previously knowncompositions and coated substrates are addressed in the presentcompositions, coated substrates, and methods.

In one aspect, the present subject matter provides a compositioncomprising 0.01% to 5% of at least one polyethyleneimine, 5% to 50% ofat least one ethylene acrylic or methacrylic acid copolymer, 0.001% to2% of at least one crosslinking agent, and 10% to 95% water.

In another aspect, the present subject matter provides a compositioncomprising 0.01% to 2% of at least one polyethyleneimine, 25% to 40% ofat least one ethylene acrylic or methacrylic acid copolymer, 0.01% to 2%of at least one crosslinking agent, and 50% to 85% water.

In yet another aspect, the present subject matter provides a coatedsubstrate adapted for receiving printing media to be applied thereon.The coated substrate comprises a substrate defining an outer surface.The coated substrate also comprises a layer of a composition disposed onat least a portion of the outer surface of the substrate. Thecomposition includes (i) 0.01% to 5% of at least one polyethyleneimine,(ii) 5% to 50% of at least one ethylene acrylic or methacrylic acidcopolymer, (iii) 0.001% to 2% of at least one crosslinking agent, and(iv) 10% to 95% water.

And, in yet another aspect, the present subject matter also provides amethod for improving ink or toner anchorage to a substrate and/orbarrier properties of the substrate. The method comprises providing asubstrate defining an outer surface to receive ink or toner. The methodalso comprises applying a composition to the outer surface of thesubstrate. The composition includes (i) 0.01% to 5% of at least onepolyethyleneimine, (ii) 5% to 50% of at least one ethylene acrylic ormethacrylic acid copolymer, (iii) 0.001% to 2% of at least onecrosslinking agent, and (iv) 10% to 95% water. A layer of thecomposition is formed on the outer surface of the substrate. And, themethod also comprises curing the layer of the composition.

As will be realized, the subject matter is capable of other anddifferent embodiments and its several details are capable ofmodifications in various respects, all without departing from thesubject matter. Accordingly, the description is to be regarded asillustrative and not restrictive.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The present subject matter provides compositions which can be used asprimer coatings or topcoats which are applied to substrates. Afterapplication and curing, the compositions provide a receiving surface forsubsequently applied printing media, for example toner and/or inks. Incertain versions of the present subject matter, the compositionsincrease bonding and/or anchorage of the toner or ink to an underlyingsubstrate.

Generally, the compositions are aqueous and comprise (i) one or morepolyethyleneimines, (ii) one or more ethylene acrylic (or methacrylic)acid copolymers, and (iii) one or more crosslinking agents. Thecompositions may optionally further comprise one or more additives forexample buffer agents, anti-blocking agents, wetting agents, defoamers,matting agents, antistatic agents, surfactants, and combinationsthereof. The present subject matter includes the use of other agentsand/or additives.

In certain versions of the present subject matter, the followingproportions of components are utilized in an aqueous, i.e. water-based,composition, as noted below in Table 1. All percentages noted herein arepercentages by weight unless indicated otherwise.

TABLE 1 Proportions of Components in Representative CompositionsEthylene Polyethyleneimine Acrylic Acid Crosslinking (s) Copolymer(s)Agent Water Typical 0.01%-5%  5%-50% 0.001%-2% 10%-95% FormulationsParticular 0.01%-2% 25%-40%  0.01%-2% 50%-85% Formulations

Details as to the various components used in the compositions of thepresent subject matter are as follows.

Polyethyleneimine(s)

Polyethyleneimine is also known as poly(iminoethylene) or polyaziridineor poly[imino(1,2-ethanediyl)]. Polyethyleneimines are either linear orbranched. Linear polyethyleneimines contain all secondary amines, incontrast to branched polyethyleneimines which can contain primary,secondary, and tertiary amino groups.

A wide array of polyethyleneimines can be used in the compositions ofthe present subject matter. For example, it is contemplated that the oneor more polyethyleneimine(s) can be linear, branched; can includealkoxylate groups, silane groups; and/or be hydroxylated. In certainversions of the compositions, a formulation of 5% polyethyleneimine inwater available from Mica Corp. of Shelton, Conn., USA under thedesignation AJ-131-X, is useful. The reference of “5%” refers to 5%polyethyleneimine solids in water. It will be understood that otherformulations including one or more polyethyleneimine(s) may be used. Forexample, certain polyethyleneimine products from BASF may also beutilized.

Ethylene Acrylic (or Methacrylic) Acid Copolymers

A wide array of ethylene acrylic (or methacrylic) acid copolymers can beused in the compositions of the present subject matter.

In certain versions of the subject matter, an ethylene acrylic acidcopolymer from Michelman, Inc. of Cincinatti, Ohio, USA, available underthe designation MP 4990 has been found to be useful. The MP 4990 productincludes 35% ethylene acrylic acid copolymer solids in water. It will beappreciated that the present subject matter includes a wide range ofethylene acrylic (or methacrylic) acid copolymers and related productsvarying in type of copolymer and percentage solids. For example, othercommercially available products containing lower solids content can beused such as 25% solids. The use of higher solids content products isalso contemplated.

The ethylene acrylic (or methacrylic) acid copolymers used in thepresent subject matter compositions typically have a molecular weight offrom about 2000 to about 100,000; and generally from about 2000 to about50,000.

The ethylene acrylic (or methacrylic) acid copolymers typically includefrom 60% to 95% ethylene and from 5% to 35% acrylic acid or methacrylicacid. However, it will be appreciated that the present subject matterincludes copolymers having proportions of ethylene, acrylic acid, and/ormethacrylic acid greater than or lesser than these amounts.

In certain versions of the present subject matter, it may be desirablethat the coating exhibit a relatively high degree of flexibility andthus be amorphous. Generally, higher amounts of acrylic or methacrylicacid lead to increased flexibility and amorphous nature. Increasedlevels of acrylic or methacrylic acid also increase polarity within thecomposition which promotes adhesion. Furthermore, higher levels ofacrylic or methacrylic acid typically result in higher temperature hottack which is desirable for HP 4000 series equipment utilizing a blankettemperature of 140° C. In addition, greater amounts of acrylic ormethacrylic acid provide a greater number of crosslinkable sites whichimproves adhesion and water resistance of the resulting coating.

Generally, higher concentrations of ethylene in the copolymer provideimproved water resistance. The use of branched polyethylene willadditionally improve the flexibility and compatibility with polyethylenefilms which can provide improved processing advantages. These advantagescan eliminate or at least reduce blocking issues which may otherwiseoccur.

Generally, ethylene segments in the ethylene acrylic (or methacrylic)acid copolymers provide properties such as increased water resistance,flexibility, crystallinity, chemical resistance and barrier properties.Long straight polyethylene chains are highly crystalline (>90%crystalline) in nature, which results in a regular packing arrangement.This is readily explained by the facility with which long polyethylenechains can align with each other.

Generally, acrylic acid imparts polarity, toughness, crosslinkability,hot tack strength, low temperature heat seal in the resulting coating.The presence of acrylic (and/or methacrylic) acid in the copolymerreduces the crystallinity of ethylene segments. Increasing the acrylic(and/or methacrylic) acid in the copolymer will result in the formationof more amorphous regions, thereby disrupting the formation of crystals.Just as the increased branching in low density polyethylene (LDPE)reduces the crystallinity of polyethylene, so will the presence ofacrylic (or methacrylic) acid. Furthermore, increasing the content ofacrylic acid will also increase adhesion of the coating to polarsubstrates, decrease softening and melting points, improve optics andincrease the strength of the coating.

Suitable ethylene acrylic (or methacrylic) acid copolymers, ordispersions of such copolymers in an aqueous vehicle, are commerciallyavailable from Michelman, Inc.; Paramelt B.V. of the Netherlands; andDow Chemical.

Crosslinking Agents

Various crosslinking agents can be utilized in the present subjectmatter.

In certain versions of the present subject matter, an aziridine basedcrosslinking agent can be used. An example of such agent is CX 100available from various suppliers.

A wide array of crosslinking agents can be used. For example, variousaziridine based, carbodiimide based, epoxy based, and/or diamineoligomers or monomers can be used instead of the noted crosslinkingagent or in combination with the noted crosslinking agent.Multifunctional isocyanates can also be used as crosslinking agent(s).

Crosslinking agents are available from various suppliers such as DSMNeoresins of Wilmington, Mass., USA; and Stahl Holland, B.V.

Alternative Embodiments

Alternatively, instead of using one or more of polyethyleneimine(s),ethylene acrylic (or methacrylic) acid copolymers, and/or crosslinkingagents; the present subject matter also includes the use of one or moreof amine end capped polyurethane and related amine-extendedpolyurethanes, ethylene vinyl acetate, vinyl acrylates, and vinylcarboxylic acid(s) and copolymers thereof. Nonlimiting examples of amineend capped polyurethanes include R-600 and/or R 563 available from DSM.Nonlimiting examples of vinyl acrylates include VYCAR® Emulsionsavailable from Lubrizol. In certain embodiments, it is contemplated toutilize vinyl acrylates and in particular emulsion systems of such forexample the noted VYCAR® systems in combination with ethylene acrylic(or methacrylic) acid or separately to provide a composition for solventinkjet printable.

Optional Additives

The present subject matter compositions can include a range of additivessuch as but not limited to buffer agents, anti-blocking agents, wettingagents, defoamers, matting agents, antistatic agents, surfactants, andcombinations thereof. It is contemplated that various colorants,pigments, dyes and similar agents can be included in the compositions ofthe present subject matter.

In certain versions of the present subject matter, a buffer agent isused to adjust or control pH of the coating composition. For example, acitrate buffer agent can be utilized. A citrate solution includingsodium citrate, i.e. Na(II) citrate, can be used. Such a solution servesas a buffer to maintain the pH of the coating composition such as forexample between 8 and 9. At pH levels greater than 9, the resultingcomposition, typically in the form of a dispersion, may not be stable.Although not wishing to be bound to any particular technique, pH of theresulting composition can be increased by adding effective amounts ofammonia to the ethylene acrylic acid copolymer component. Alternatively,pH can be reduced by appropriate formulating techniques of thepolyethyleneimine component.

Buffer or buffering agents are available from suppliers such as SigmaAldrich of St. Louis, Mo., USA.

Antiblocking agents are available from Paramelt and under thedesignation AQUASAFE from Nazdar Ink Technologies of Shawnee, Kans.,USA, for example.

Wetting agents are available from Ashland Inc. of Ashland, Ky., USA andLubrizol Corp. of Cleveland, Ohio, USA.

Defoamers are available from Ashland and Michelman.

Matting agents are available from Evonik Industries of Germany; Rhodia amember of Solvay Group Worldwide; and AKZO Nobel.

Antistatic agents are available from Akzo and Croda of Yorkshire, UK.

Compositions

The compositions of the present subject matter generally include waterwith a total solution solids content of about 10%. However, it will beappreciated that the proportion of solids dispersed in water can varydepending upon a host of factors such as coating technique, substratecharacteristics, and environmental factors. The present subject matterincludes the use of compositions having a total solution solids contentof less than 10%.

The compositions as described herein include water and in manyembodiments, include a majority proportion of water. Water serves as avehicle for the various components, i.e. the polyethyleneimine(s),ethylene acrylic (or methacrylic) acid copolymer(s), and thecrosslinker(s). However, the present subject matter includes the use ofother vehicles and/or solvents in the compositions such as for exampleorganic agents and a wide array of alcohols.

Coatings

As previously noted, the present subject matter also includes coatingsor layers which are deposited or otherwise formed on substrates. For acoating composition having 10% solids, a dry coatweight for polymericfilm substrates can for example range from about 0.3 gsm to about 0.5gsm. For paper substrates, a coating composition having 25% solids canbe used to form a dry coatweight ranging from about 0.8 gsm to about 1.2gsm.

After application of the composition to a substrate, the composition iscured. Typically, curing is performed by drying the applied or depositedcomposition to remove water and/or other vehicles and then subjectingthe composition to a crosslinking operation. Drying and crosslinking canbe performed sequentially or concurrently. Typically, water is removedby heating such as by use of a convection oven, an air flow oven, and/orby an NIR oven. The temperature range within such ovens is typicallybetween 45° C. and 70° C.

Crosslinking can be performed by several techniques. Typically,crosslinking is achieved by heating the composition and removing waterfrom the composition. In certain versions of the present subject matter,crosslinking can be performed or initiated during or after drying andtriggered by a change in pH from alkaline to acidic. Typically, thisoccurs during drying. The change in pH can result due to evaporation ofammonia or other neutralizing agent from the composition.

Substrates

The various compositions can be applied to regions or faces ofsubstrates and cured to provide a coating, layer, or other surfacehaving desired properties such as improved ink anchorage. Nonlimitingexamples of substrates include paper substrates, polymeric filmsubstrates, and composite substrates that include paper and filmcomponents.

Paper substrates are particularly useful because of the wide variety ofapplications in which they can be employed. Any type of paper havingsufficient tensile strength to be handled in conventional paper coatingand treating equipment can be employed as the substrate layer. Thus, anytype of paper can be used depending upon the end use and particularpersonal preferences. Included among the types of paper which can beused are paper, clay coated paper, glassine, polymer coated paper,paperboard from straw, bark, wood, cotton, flax, cornstalks, sugarcane,bagasse, bamboo, hemp, and similar cellulose materials prepared by suchprocesses as the soda, sulfite or sulfate (Kraft) processes, the neutralsulfide cooking process, alkali-chlorine processes, nitric acidprocesses, semi-chemical processes, etc. Although paper of any weightcan be employed as a substrate material, paper having weights in therange of from about 20 to about 150 pounds per ream are useful, andpapers having weights in the range of from about 30 to about 60 poundsper ream are typical. The term “ream” as used herein equals 3000 squarefeet. Examples of specific papers which can be utilized as substrates inpreparing the coated substrates of the present subject matter include41-pound offset grade bleached Kraft; 50-pound bleached Kraft paper,etc.

Generally, the polymeric film materials may be selected frompolystyrenes, polyolefins, polyamides, polyesters, polycarbonates,polyvinyl alcohol, poly(ethylene vinyl alcohol), polyurethanes,polyacrylates, poly(vinyl acetates), ionomers and mixtures thereof. In aparticular embodiment, the polymeric material is a polyolefin such aspolyethylene or polypropylene.

Other materials for the polymeric film layer include meltablefilm-forming substances used alone or in combination, such aspolyethylene, methyl polyacrylic acid, polyethylene ethyl acrylate,polyethylene methyl acrylate, acrylonitrile, butadiene, styrene polymer,nylon, polybutylene, polystyrene, polyurethane, polysulfone,polyvinylidene chloride, polypropylene, polymethyl pentene, styrenemaleic anhydride polymer, styrene acrylonitrile polymer, ionomers basedon sodium or zinc salts of ethylene/methacrylic acid, polymethylmethacrylates, cellulosics, fluoro plastics, polyacrylonitriles, andthermoplastic polyesters.

The present subject matter includes one or more substrates having atleast one layer or region of a composition as described herein,deposited thereon. Thus, the present subject matter includes coatedsubstrates or substrates having layers or coatings of the primer ortopcoat compositions described herein.

Methods

The present subject matter also provides methods of improving ink ortoner anchorage to a substrate surface. The subject matter also providesmethods of improving barrier properties of a print receiving surface.The methods comprise applying a layer or coating of a compositionaccording to the present subject matter onto a face or region of asubstrate followed by curing of the applied layer, e.g. drying andcrosslinking of the composition to thereby form a topcoat on thesubstrate. The compositions can be applied by known techniques such asby spraying and/or by roller deposition. And drying of the appliedcoating can also be performed by known techniques. Crosslinking isperformed based upon the type of crosslinking agent(s) in thecomposition. However, for many applications, crosslinking can beperformed by exposure to UV light.

In certain applications, it may be beneficial to utilize coronatreatments on one or more faces of films or substrates prior to applyingthe compositions of the present subject matter. For example, prior toapplying certain topcoat formulations to polypropylene and/or metalizedfilms, it may be advantageous to utilize 50 to 150 W/m²/min coronatreatment to the surface of the films.

Applications

In addition to the various applications and uses described herein, thecompositions of the present subject matter can also be utilized inapplications involving UV inkjet applications, latex applications, andthermal transfer applications. For example, in UV inkjet applications,the compositions of the present subject matter can be used for formingtopcoats on substrates that then receive printing from UV curable inksapplied by inkjet printing. Latex applications may involve for example,latex based inks from certain printers that dispense such inks such ascertain printers available from Hewlett-Packard. The compositions of thepresent subject matter can be used for forming topcoats on substratesthat then receive printing of latex based inks. And, the present subjectmatter compositions may also be suitable for forming topcoats which thenreceive printing from thermal transfer printing methods and/or devices.In particular versions of the present subject matter, the topcoats mayexhibit characteristics enabling their use in two or more of theseapplications, and potentially in further combination with otherapplications. For example, a topcoat formulation in accordance with thepresent subject matter and that comprises simple ethylene acrylic acidand crosslinker can be used for both thermal transfer printing and latexbased ink printing.

EXAMPLES

A series of evaluations were conducted to assess the performance andcharacteristics of several coating compositions according to the presentsubject matter. Specifically, three compositions were prepared as notedin Table 2 below. In Table 2, the “AJ-131-X” component is a solution of5% polyethyleneimine in water having a pH of 10, available from MicaCorp. The “EXP 1232/MP 4990” component is a dispersion of 25% solids ofethylene acrylic acid copolymer in water available from Michelman, Inc.The “CX 100” is an aziridine based crosslinker. And the citrate agent isa buffer agent in the form of Na(II) citrate. The compositions wereapplied to substrates and topcoats formed. UV Flexo printing performanceand HP Indigo printing performance were then assessed as describedbelow.

TABLE 2 Representative Compositions and Performance UV HP Flexo IndigoEXP Printing Printing AJ-131-X 1232/MP Citrate CX Perfor- Perfor- (5%)4990 (25%) (1%) 100 Water mance mance 0.028% 33.003% 0.226% 0.200%66.543% 80% 100% 0.028% 32.904% 0.226% 0.498% 66.344% 60%  90% 0.028%32.741% 0.225% 0.990% 66.016% 50%  50%

UV Flexo printing performance was evaluated as follows. Ink anchoragewas determined with a Flexiproof 100 UV testing unit equipped with abanded anilox roller with bands of 3, 4, 5, 6, 8 and 13 cc/m². The inkused was XSYS Flexocure Gemini, process magenta. Samples were cut to12.5×10 cm and mounted on the press. Immediately after printing, twostrips of Scotch tape 810 were firmly pressed on the printed surface,and left for 5 seconds. The tape was pulled off (180°, as fast aspossible) and kept for analysis. Each sample was printed at 80, 50 and20 m/min. The tape was adhered on a piece of paper, and the paper wasscanned (B/W, 300 dpi). The resulting image was analyzed with Image)software 2, and the mean gray density of a 170×1000 pixel area wascalculated. This resulted in a value between 70 (all ink pulled off) and255 (no ink pulled off). The ultimate value for ink anchorage wasobtained by averaging the values of each tape, at all three speeds(total 6 data points). High values indicate better anchorage. The valuespresented in Table 2 were converted to percentages based upon 100%corresponding to no ink being pulled off, i.e. a value of 255.

HP Indigo printing performance was performed according to standard HPindigo test format. Ink anchorage was tested by Scotch 810 tape test forfilm substrates and Scotch 3M 230 tape test for paper substrates. Thepercentage anchorage was relative. 100% means no ink delamination atall.

As noted in Table 2, the compositions of the present subject matterexhibited good to excellent results in terms of their UV Flexo and HPIndigo printing performance, i.e. at least 50%.

In another set of evaluations, water resistance of the UV Flexo printedsamples was assessed by heating UV Flexo printed polypropylene films at40° C. and 90° C. for 1 hour and 30 minutes, respectively. Ink anchoragewas tested using Scotch tape 810. All samples exhibited excellentperformance. This was tested for both film and paper substrates. Allsamples received a score of 10 (on a scale of 1 to 10), with nodelamination occurring in any of the samples.

In still another set of evaluations, topcoat coverage was also assessed.This evaluation was performed by depositing standard malachite dye onpaper substrates and shirlastein dye on film substrates. All samplesexhibited very good coverage.

Many other benefits will no doubt become apparent from futureapplication and development of this technology.

All patents, applications, and articles noted herein are herebyincorporated by reference in their entirety.

As described hereinabove, the present subject matter solves manyproblems associated with previous strategies, systems or devices.However, it will be appreciated that various changes in the details,materials and arrangements of components and operations, which have beenherein described and illustrated in order to explain the nature of thesubject matter, may be made by those skilled in the art withoutdeparting from the principle and scope of the subject matter, asexpressed in the appended claims.

What is claimed is:
 1. A composition comprising: 0.01% to 5% of at leastone polyethyleneimine; 5% to 50% of at least one ethylene acrylic ormethacrylic acid copolymer; 0.001% to 2% of at least one crosslinkingagent; and 10% to 95% water.
 2. The composition of claim 1 wherein thecomposition comprises an ethylene acrylic or methacrylic acid copolymerhaving a molecular weight of from 2,000 to 100,000.
 3. The compositionof claim 2 wherein the molecular weight is from 2,000 to 50,000.
 4. Thecomposition of claim 1 wherein the copolymer has an ethylene content of60% to 95%.
 5. The composition of claim 1 wherein the copolymer has anacrylic acid or methacrylic acid content of 5% to 35%.
 6. Thecomposition of claim 1 wherein the crosslinking agent is selected fromthe group consisting of aziridine based agents, carbodiimide agents,epoxy agents, diamine oligomers or monomers, multifunctional isocyanatesand combinations thereof.
 7. The composition of claim 1 furthercomprising at least one agent selected from the group consisting ofbuffer agents, anti-blocking agents, wetting agents, defoamers, mattingagents, antistatic agents, surfactants, and combinations thereof.
 8. Acomposition comprising: 0.01% to 2% of at least one polyethyleneimine;25% to 40% of at least one ethylene acrylic or methacrylic acidcopolymer; 0.01% to 2% of at least one crosslinking agent; and 50% to85% water.
 9. The composition of claim 8 wherein the compositioncomprises an ethylene acrylic or methacrylic acid copolymer having amolecular weight of from 2,000 to 100,000.
 10. The composition of claim9 wherein the molecular weight is from 2,000 to 50,000.
 11. Thecomposition of claim 8 wherein the copolymer has an ethylene content of60% to 95%.
 12. The composition of claim 8 wherein the copolymer has anacrylic acid or methacrylic acid content of 5% to 35%.
 13. Thecomposition of claim 8 wherein the crosslinking agent is selected fromthe group consisting of aziridine based agents, carbodiimide agents,epoxy agents, diamine oligomers or monomers, multifunctional isocyanatesand combinations thereof.
 14. The composition of claim 8 furthercomprising at least one agent selected from the group consisting ofbuffer agents, anti-blocking agents, wetting agents, defoamers, mattingagents, antistatic agents, surfactants, and combinations thereof.
 15. Acoated substrate adapted for receiving printing media to be appliedthereon, the coated substrate comprising: a substrate defining an outersurface; and a layer of a composition disposed on at least a portion ofthe outer surface of the substrate, the composition including (i) 0.01%to 5% of at least one polyethyleneimine, (ii) 5% to 50% of at least oneethylene acrylic or methacrylic acid copolymer, (iii) 0.001% to 2% of atleast one crosslinking agent, and (iv) 10% to 95% water.
 16. The coatedsubstrate of claim 15 wherein the composition comprises an ethyleneacrylic or methacrylic acid copolymer having a molecular weight of from2,000 to 100,000.
 17. The coated substrate of claim 16 wherein themolecular weight is from 2,000 to 50,000.
 18. The coated substrate ofclaim 15 wherein the copolymer has an ethylene content of 60% to 95%.19. The coated substrate of claim 15 wherein the copolymer has anacrylic acid or methacrylic acid content of 5% to 35%.
 20. The coatedsubstrate of claim 15 wherein the crosslinking agent is selected fromthe group consisting of aziridine based agents, carbodiimide agents,epoxy agents, diamine oligomers or monomers, multifunctional isocyanatesand combinations thereof.
 21. The coated substrate of claim 15 furthercomprising at least one agent selected from the group consisting ofbuffer agents, anti-blocking agents, wetting agents, defoamers, mattingagents, antistatic agents, surfactants, and combinations thereof. 22.The coated substrate of claim 15 wherein the composition includes (i)0.01% to 2% of at least one polyethyleneimine, (ii) 25% to 40% of atleast one ethylene acrylic or methacrylic acid copolymer, (iii) 0.01% to2% of at least one crosslinking agent, and (iv) 50% to 85% water.
 23. Amethod for improving ink or toner anchorage to a substrate and/orbarrier properties of the substrate, the method comprising: providing asubstrate defining an outer surface to receive ink or toner; applying acomposition to the outer surface of the substrate, the compositionincluding (i) 0.01% to 5% of at least one polyethyleneimine, (ii) 5% to50% of at least one ethylene acrylic or methacrylic acid copolymer,(iii) 0.001% to 2% of at least one crosslinking agent, and (iv) 10% to95% water, to thereby form a layer of the composition on the outersurface of the substrate; and curing the layer of the composition. 24.The method of claim 23 wherein curing is performed by drying thecomposition and inducing crosslinking of the composition.
 25. The methodof claim 23 wherein the composition includes an ethylene acrylic ormethacrylic acid copolymer having a molecular weight of from 2,000 to100,000.
 26. The method of claim 25 wherein the molecular weight is from2,000 to 50,000.
 27. The method of claim 23 wherein the copolymer has anethylene content of 60% to 95%.
 28. The method of claim 23 wherein thecopolymer has an acrylic acid or methacrylic acid content of 5% to 35%.29. The method of claim 23 wherein the crosslinking agent is selectedfrom the group consisting of aziridine based agents, carbodiimideagents, epoxy agents, diamine oligomers or monomers, multifunctionalisocyanates and combinations thereof.
 30. The method of claim 23 whereinthe composition further includes at least one agent selected from thegroup consisting of buffer agents, anti-blocking agents, wetting agents,defoamers, matting agents, antistatic agents, surfactants, andcombinations thereof.
 31. The method of claim 23 wherein the compositionincludes (i) 0.01% to 2% of at least one polyethyleneimine, (ii) 25% to40% of at least one ethylene acrylic or methacrylic acid copolymer,(iii) 0.01% to 2% of at least one crosslinking agent, and (iv) 50% to85% water.